Batch Observations

Joachim Köppen Strasbourg 2010

Only when you are well familiar how to do observations manually and when you start systematic observations, perhaps at inconvenient times, then you can turn using batch operating.

The telescope can be operated in batch mode, i.e. without the direct control of the user. For this purpose we prepare a text file which contains all the commands we plan to issue during the observation run. However, we should take care that we do not demand the telescope to go to a source which at that moment happens to be below the horizon ... in this case the telescope will retire to its stow position.

Such a run may be short, and we might simply sit in front of the computer watching the incoming results. This may be useful during tests, such as the ones we need to excute because of the strong interference: All commands are stored in the file and are executed in the prescribed manner ... so that it won't happen that we forget something ;-)

We can also run the telescope for a longer run, such as overnight, or during times we cannot be present. In this case, it is useful to plan ahead, as to ensure that the telescope is not pointed at objects below the horizon. For this purpose, we can use the planning applet or the trainer applet to check the visibility of your sources.

To run ESA-Haystack in batch mode, you click the CmdFile button, upon which a window opens with a file selection menu. You select your file ... The program then reads and execute one line after the other of the file. The commands are displayed in the lower right hand corner.

In case you want to change something in the file, such as modifying the interation time, having seen the previous results, you may do so: simply open the file with the text editor, apply the changes or add anything, and then save it. Obviously, you can only change lines that have not yet been read by the program!

The rules for the command file text are:

The keywords are (items in [ ] are optional):

For example: a solar observation would entail measurement of the solar flux, the background of the empty sky, and the flux from the ISU library wall, which can serve as a flux calibrator source
:  pointcorr -0.5 -3.5apply the pointing correction
:  freq 1420 1set centre frequency 1420 MHz and span 500 kHz
:  recordstart recording
:  Sungoto Sun
:600measure for 10 min
:  offset -90 0offset 90 east of Sun, same elevation
:600measure for 10 min
:  ISUgoto ISU wall for flux calibration
:600measure for 10 min
:  roffstop record
:  stowgoto stow position
Note that the seconds to wait is right next to the :    but otherwise there is always a space before the command keyword!

It is a good idea to keep an eye on the telescope, during the beginning of each batch run, just to be sure that everything works as it should!

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last update: Apr. 2010 J.Köppen